Towers of Power

The term “carbon footprint” is often applied to industrial facilities, where significant consumption of various forms of energy is measured against the effects on the environment as compared to the product output. In the hospitality, gaming and resort industries, the energy impact is clearly not trivial. If you take a walk through a casino at 3 a.m., you will think it is the middle of the day with a lot of energy-consuming lights and sounds.

Though there aren’t published energy consumption data of such, it is undeniable that these footprints are significant with the lights, elevators and air conditioning running 24 hours a day. This is especially true in the desert where temperatures are more than 100 degrees outside and 68 degrees inside. But a recent trip overseas reminded me of things that could be done to reduce this footprint without dampening the glitter that is part of the allure of the industry and without compromising the power quality for reduced power quantity.

Let’s start with the ride up the elevator to the 23rd floor. Use of adjustable speed drives (ASD) to control the elevators allows for maximum power for acceleration while reducing consumption once up to speed. The rectified input of the power supply section turns the 50/60 Hz AC into DC before turning it back into AC voltage at a different and variable frequency, which is how the speed is modified since that is what controls the revolution per minute (rpm) of the motor.

By nature of the rectifier, the current is nonlinear, which results in harmonics. So, while less power consumptions reduces one form of pollution, another form of pollution is increased, namely the “harmonic” pollution unless proper filters are also installed.

Exiting the elevator into the hallway of the 23rd floor was another enlightening experience—also another opportunity for energy conservation. The use of motion sensors to activate the hall lights would reduce the lighting load in the hallways significantly. Except during spring break when the room parties overflow, the hallways are probably unoccupied more than 90 percent of the time, yet the lights are on all the time. Though one could argue that the constant turning on and off of the lights would shorten the life of the light bulbs, which would require more to be produced (increasing the carbon footprint of the manufacturer). However, I think this tradeoff is an overall win in the net sum game.

Opening the door to your room, you’ll sometimes feel a blast of cold air from the AC that was cranked up earlier (but not turned down when exiting the room), along with a number of lights and TV left on. On occasion, there will be the need to go back down to the front desk because you left the key card to open the door in the room. These situations can be eliminated by installing a card detection sensor just inside the door, where the occupant must insert the room key in order to activate the lights and AC controls. Remove the key and only one safety light comes on, while the AC is set to a reasonable level. Put the key card in, and the light switches, outlets and AC controls now all work. And the key card is always right by the door, obvious to the occupant when exiting the room and automatically turning off the energy-consuming equipment. Not only is the energy conserved, but the impact on the power quality is only positive by reducing the harmonic loads caused by the unnecessary operation of the TV and HVAC when the room is unoccupied. This technology is common in many other countries and seems to work just fine.

Changing lighting sources to more efficient types is another way to reduce the carbon footprint, though the glittering lights on the Las Vegas Strip will probably never be converted to LED-based lighting. Nor is it likely that the thousands of cars and taxis cruising up and down all day and night ever be replaced with energy-efficient people movers. But then again, the aforementioned methods of “shrinking shoe sizes” are not limited to Las Vegas, Atlantic City or even just the gaming industries. The thousands of hotels throughout the country and the world could all contribute to this reduction with a relatively small capital investment.

Reducing the energy consumption and the resulting pollution from its generation is a process that moves just one bulb at a time.

BINGHAM,a contributing editor for power quality, can be reached at 732.287.3680.